Integrated circuitry may include CMOS (complementary metal oxide semiconductor); with a CMOS structure comprising a PMOS (p-type metal oxide semiconductor; i.e., positive channel metal oxide semiconductor) transistor and an NMOS (n-type metal oxide semiconductor; i.e., negative channel metal oxide semiconductor) transistor. It is desired to develop improved CMOS architectures having PMOS and NMOS transistors tailored to achieve desired operational parameters, and to develop methods for fabricating such CMOS architectures.